1. Field of Invention
The present invention relates to a single layer capacitive touch module, and more particularly, to a soft board (or flexible board, flexible printed board, etc.) design for a single layer capacitive touch module.
2. Description of Prior Art
Refer to FIG. 1 and FIG. 2. FIG. 1 is a drawing for a layout pattern on a single layer capacitive touch module of a prior art. FIG. 2 is a drawing for a soft board design for a single layer capacitive touch module of a prior art. As FIG. 1 shows, a sensor dot matrix 13 comprises M×N sensor dots forming by M driving lines 16 (T1-Tm) intersecting N sensing lines 17 (R1-Rm). In the prior art, the M×N sensor dots need to be individually wired to a coupling area of the sensor dot matrix, then connected with a lead-in area 12 of a soft board 14. Because the lead number of the lead-in area 12 of the soft board 14 should be the same as the lead number of the sensor dots 15, the width of the soft board 14 is accordingly wide. A lead-out area 18 of the soft board 14 opposite the lead-in area 12 of the soft board 14 is too wide to dispose the soft board 12 on an OLB (Outer Lead Bonding) area, making a crowding effect in space distribution on the soft board 12 and the other units of the touch module (not shown).
FIG. 3 is a drawing for a soft board design for a single layer capacitive touch module of another prior art. The difference between FIG. 2 and FIG. 3 is that a double layer soft board 21 is used. A layout pattern 23 is provided on the double layer soft board 21 to implement the bridge connection of the M driving lines 25 (T1-Tm), as a result, the lead number of a lead-out area 24 of the double layer soft board 21 can substantially decrease. Because the width and thickness of a lead-in area 22 of the double layer soft board 21 are too large, the double layer soft board 21 is hard to bend and accordingly the application of the double layer soft board 21 is limited.